Garra borneensis (VAILLANT, 1902)

SynonymsTop ↑

Discognathus borneensis Vaillant, 1902

Etymology

Garra: vernacular Gangetic name for a particular species of “sand-digger,” which Francis Buchanan-Hamilton applied as a generic name for bottom-dwelling cyprinids “with no affinity to another genus”.

borneensis: ‘from Borneo’.

Classification

Order: Cypriniformes Family: Cyprinidae

Distribution

Endemic to northern and western Borneo, where it has been recorded from numerous river basins in Kalimantan, the Indonesian portion of the island, with additional records from Brunei Darussalam and the Malaysian provinces of Sabah and Sarawak.

Type locality is ‘Indonesia: Borneo: Kalimantan Timur: Bloeoe River [Bluu, 0°42’N 114°24’E]’.

Habitat

An obligate dweller of swiftly-flowing streams and headwaters containing clear, oxygen-saturated water. It often inhabits riffles and runs and is likely to show a preference for shallower zones.

Substrates are generally composed of gravel, rocks, boulders or bedrock carpeted with a rich biofilm formed by algae and other micro-organisms.

At a habitat in the Mendawai river basin in central Kalimantan, H. borneensis was collected from a foothill stream running swiftly over a rock and gravel substrate with clear water of pH 6.4.

Other fish species included Paracrossocheilus vittata, Rasbora elegans, Homaloptera orthogoniata, Homalopteroides stephensoni, and Nemacheilus spiniferus, plus unidentified species of Hypergastromyzon, Gastromyzon and Glyptothorax.

Maximum Standard Length

90 – 115 mm.

NotesTop ↑

G. borneensis is the only member of the genus known from Borneo, and thus Indonesia.

The genus Garra is a particularly enigmatic grouping with new taxa described on a regular basis, while many of the existing ones may represent cases of misidentification or synonyms of other species. Some of the revisions have also been called into question, which has added further confusion. A full generic review would be ideal but is unlikely to materialise given the extensive distribution of its members which range from southern China across much of southeast Asia, India and the Middle East as far as north/central Africa.

Instead a number of less-extensive works published in recent years have resulted in a gradual, but continuing, improvement in knowledge, and it remains possible that the genus will be broken up into smaller taxa since the current assemblage is almost certainly polyphyletic.

Garra species are usually included in the subfamily Labeoninae/Cyprininae or tribe Labeonini (name varies with author) which by recent thinking is further divided into four subtribes; Labeoina, Garraina, Osteochilina, and Semilabeoina (Yang et al., 2012). The putatively monophyletic Garraina comprises a number of genetic lineages including Garra sensu stricto (which also includes Horalabiosa, Phreatichthys and possibly other genera), a small clade comprising Garra cambodgiensis and G. fascicauda (thus rendering Garra polyphyletic), Paracrossocheilus, and Gonorhynchus (which includes Akrokolioplax).

Two Garra species, G. imberba and G. micropulvinus, are placed in the Semilabeoina assemblage, and the generic name Ageneiogarra Garman, 1912 has been suggested for them, although this does not appear to have been widely followed (e.g. Kottelat, 2013). In addition, some genera which were previously considered to be close relatives of Garra species such as Discogobio, Discocheilus and Placocheilus, are now also placed in this subtribe.

All genera currently included in Garraina possess a lower lip modified to form a mental adhesive disc, allowing the fish to cling to surfaces in turbulent conditions. In most species the upper lip is almost entirely reduced and both the upper and lower jaw margins are keratinised, i.e., horny, and used to scrape food items from the substrate.

Garra species are distinguished from other Garraina members by the first two pectoral-fin rays usually being thickened, fleshy and unbranched, possession of 10-11 dorsal-fin rays, and a combination of internal characters. Some species have evolved particular environmental specialisms such as highly reduced eyes in hypogean forms or the ability to survive in thermal springs.

References

1. Vaillant, L. L., 1902 - Notes from the Leyden Museum v. 24 (note 1): 1-166
   Résultats zoologiques de l'expédition scientifique Néerlandaise au Bornéo central. Poissons.
2. Kottelat, M., 2013 - Raffles Bulletin of Zoology Supplement 27: 1-663
   The fishes of the inland waters of southeast Asia: a catalogue and core bibiography of the fishes known to occur in freshwaters, mangroves and estuaries.
3. Martin-Smith, K. M. and H. H. Tan, 1998 - Raffles Bulletin of Zoology 46(2): 573-604
   Diversity of freshwater fishes from eastern Sabah: annotated checklist for Danum Valley and a consideration of inter- and intra-catchment variability.
4. Parenti, L. R. and K. K. P. Lim, 2005 - Raffles Bulletin of Zoology Supplement 13: 175-208
   Fishes of the Rajang Basin, Sarawak, Malaysia.
5. Roberts, T. R., 1989 - Memoirs of the California Academy of Sciences No. 14: i-xii + 1-210
   The freshwater fishes of western Borneo (Kalimantan Barat, Indonesia).
6. Yang, L., M. Arunachalam, T. Sado, B. A. Levin, A. S. Golubtsov, J. Freyhof, J. P. Friel, W-J. Chen, M. V. Hirt, R. Manickam, M. K. Agnew, A. M. Simons, K. Saitoh, M. Miya, R. L. Mayden, and S. He, 2012 - Molecular Phylogenetics and Evolution 65(2): 362-379
   Molecular phylogeny of the cyprinid tribe Labeonini (Teleostei: Cypriniformes).